The network operation failed with the following ERROR: During network request: Unknown reason.

[Ebony-angel]

On my Linux Mageia 7, I have a VM with Windows 7 Home Basic 64-bit SP1. Currently runs Guest Additions 5.2.32r132073.

When I try to download a more updated version of Guest Additions (to support OpenGL and Direct3) I receive the following message:

The network operation failed with the following error:
During network request: Unknown reason.

What is the reason and how can I fix it?

(Updated to add "of Guest Additions")

[scottgus1]

When I try to download a more updated version

If this refers to updating Virtualbox, and you are downloading from your Linux distro's repository, then unfortunately you'd have to ask them.

If you are trying to install from https://www.virtualbox.org/wiki/Linux_Downloads, then maybe the website is having a slowdown? Try a complete host PC reboot and try the download again.

[Ebony-angel]

Sorry if, due to my basic english, I did not make it clear what I intended to update.

I intend to update the Guest Additions.

I try it in Windows 7 VM, with Devices menu / Insert CD image.

[scottgus1]

Googling "The network operation failed with the following error: During network request: Unknown reason" brings up this: https://bugs.archlinux.org/task/61586, indicating you might be using your Linux distro's version of Virtualbox. (apparently the Guest Additions ISO hasn't been downloaded from the distro yet?)

Distros fork Virtualbox with possible changes, and we don't know what they changed. We can only support Virtualbox installed from https://www.virtualbox.org/wiki/Linux_Downloads. The official Virtualbox comes with the GAs ISO built-in.

[anylocalserver]

Got this error when I clicked VirtualBox → Check for Updates on 5.2 running on Mac OS X. Turns out, this could be because 5.2 is now discontinued, according to the official Downloads page:

Please also use version 5.2 if you still need support for 32-bit hosts, as this has been discontinued in 6.0. Version 5.2 will remain supported until July 2020.

Manually downloading and installing 6.0 has fixed this.

[scottgus1]

5.2 is now discontinued

It's more like 32-bit host OS support in 6.0.x & later is discontinued. 5.2.44 for 32-bit hosts is still available and was released July 2020.